Did Facebook censor an article critical of Narendra Modi?

People on Twitter are venting their anger after an article about Prime Minister Narendra Modi's visit to the UK in 2003 disappeared from their Facebook timeline and they were unable to share it again.

Despite Facebook's clarification that the company did not block the piece and its engineers were looking into reasons as to why it disappeared, speculation on Twitter that Facebook might have taken the story down because of the close relationship between its CEO Mark Zuckerberg and Modi has not stopped.

Zuckerberg, who hosted PM Modi at Facebook's Silicon Valley headquarters in September, is trying hard to woo the Indian government to push his company's controversial Free Basics (formerly Internet.org) project in India.

The article titled 'When Mr Modi Went To London' has been written by Satyabrata Pal, who was India's deputy high commissioner in London during Modi's visit to the United Kingdom, for The Wire on November 17.

Pal said he wrote the piece to "keep the record straight" about Modi's visit to London as the chief minister of Gujarat, adding that it was a "nerve-racking and politically fraught affair" unlike what the Prime Minister recently claimed.

The piece was shared on Facebook over a thousand times until it vanished. Worse, people were unable to share it on Facebook anymore, and were simply greeted with an error message from the world's largest social network that the content they were trying to post was "abusive".

Siddharth Varadarajan, the editor of The Wire, tweeted:

Across Twitter, users were puzzled and outraged:

"I am as mystified as everyone else, quite frankly," Varadarajan told Hindustan Times.

"There is one theory that a section of people on the internet perhaps reported Satyabrata Pal's article on The Wire as abusive en masse, triggering a Facebook response, but I have yet to receive any reply or response or clarification from Facebook."

When Hindustan Times tried to post the link to the piece on Facebook early on Thursday, this error popped up:

The message suggests that Facebook's system has an issue with a the story's lead image (notice the '.jpg' at the end of the link?) rather than the story itself.

San Francisco-based developer Subhasish Das has a theory about why this could have happened.

"It's based on the screenshot [above]", Das said.

He thinks pages of The Wire appear to be configured to load various resources (images, Javascript, text, and more) from an IP address, instead of a regular web address (a URL), that we can all read and understand.

"One of the things that this particular page links to and can thus be potentially pinged from a browser once someone loads the page, is a script that all Wordpress pages usually contain," he said. "This script may cause security issues at times, and my theory is that Facebook's spam or security filters was reacting to it and blocked it."

When Hindustan Times reached out to Facebook, the company confirmed Das' theory.

"The content was mistakenly captured by our spam filter and has now been restored. We are sorry for the error and inconvenience caused," a Facebook spokesperson said.

The speculations, however, are not without basis.

According to the company's annual Government Requests report , India tops the list of countries for censoring content on Facebook. In 2015, India made 15,155 demands, outnumbering 92 other countries in the list, compared to 5,832 requests between June and December 2014, says the report.